Apparatus for handling chipper knives



May 17, 1949;

s. D. PAYZER APPARATUS FOR HANDLING CHIPPER KNIVES Filed Oct. 9, 1944 IN V EN TOR.

wwl az m/ ATTORNEYS.

Patented May 17, v1949 U NIT E D S TAT'ES PATENT F F HIE,

2,417.0;261 APPARATUS Fon- HANDEING CHIPPER KNIVES Stanley D..Payzer, Wausau, Wis., assignor'to D. J. Murray Manufacturing 00., Wausau, Wis., a corporation of Wisconsin Application Ootober9, 1944; Serial' Nm557-, 808

3 Glaimss' (Cl. -1441-"Z6Y) Myinvention relates generally toimprovements the art of handling wood chipper knives, and relates: more specifically to improved apparatus for expediting insertion and removal of the cutting blades of rotary w ood' chippers relative'to their carrier rotors or discs.

Rotary wood chippers each comprising a rapidly revolvabl e disc provided with an annular series of radially disposed. knives having cutting edges protruding from one side face of the disc and cooperating with a hopperfor feeding logs or wood slabs at a downward'inclination toward said disc face on one side of the rotor axis, have lohgbeen employed in the paper manufacturing industry. The cutting blades or knives of these machines must be frequently removed for regrinding or replacement, and while the removal and reinsertion of the blades may be a relatively simple matter in very small machines, the knives of the larger ohi'ppers are relatively heavy and bulky and extremely dangerous to handle. Then too, after the cutting blades have been in use for some time, they often become jammed within their confining openings, and can'be dislodged only with great effort; and the timeconsumed and waisted by the prior tedious methods of manually inserting and removing such knife blades has always been a source of annoyance and expense to the operators. While the chipper knives are notreadily accessible for insertion and removal at the zone of the feed hopper, free access to the cutting; blades may be had on the side of the rotor axis opposite to the hopper; and although this available space remote from the hopper has heretofore been used for inserting and removing the knives, it previously was necessary to also remove various other partsof the rotor assemblages in order to apply or withdraw the cutting blades, thereby making these operations both difficult and dangerous.

It-is therefore an object of my present invention to provide improved apparatus for effecting insertion and removal of the knives of rotary chippersor thelike in a safe and expeditious manner, and with minimum loss of time,

Another objectof the present invention is to provide new and useful instrumentalitiesfor facilitating the rapid removal and application of chipper blades, from and totheir carrier discs, without necessitating complete removal of the normal-knife retaining elements ofthe. rotor ass'emblage.

A. further object of this invention to provide simple andeffective apparatus for quickly dis-'- lodging and removingv chipper knife blades, and

2 f orsafely manipulating the cutting, members duringinsertion and removal thereof.

Still; another object of my invention is tcpro videimproved apparatus for safely and. expeditiously handling. chipper knives or the like, so, as to reduce to a'minimum the. danger and the time lost in reconditioning. or renewing such knives.

These and other objects and advantages of the invention will be apparent from the following detailedv description.

A clear conception of the several features involved in. my improvement for handling. chipper knives; and of the construction and operation of one type ofv apparatus which may be used in. com mercial exploitation of the invention, may be had by referring; to: the drawing accompanying and forming. a part of this specification wherein like reference characters designate the same orsimilar parts in the various views.

Fig. I. is-a relatively large fragmentary section through a chipper rotor takenacross one of the knife or blade assemblages, and showing a knife blade being forced upwardly out of its normal retaining slot and engaged by a suspension clamp or'tongs';

Fig. 2 is: a somewhat reduced-side elevation of a chipper knife engaged by and suspended from one" of the improved handling tongs;

Fig. 3"is a further reduced-diagrammatic side view ofa typical rotary chipper disc showing the approximate normal disposition of the radiating knives, and the relative position of the feeding hopper or spout; and

Fig. 4 is a perspective view of the elements used to initially-forcethe knife bladesout of their normal'confin-ing slots, in accordance with the presentinvention.

While the inventionhas beenshown and de= scribed herein as being especially useful inconjunction with chipper knife assemblages ofa particular type, it is in fact more generally applicable and it: is not my desire or intent to unnecessarily restrict the scope or utility of the improvement by virtue of this specific disclosure.

Referring tothe drawing, the rotary chipper and knife assemblage specifically shown, com prisesin: general a chipper rotor or rotary disc 5 mounted for rapid rotation upon a central shaft 6 and having an annular series of elongated ap proximately radial through openings or slots 1 therein; achipper blade or knife 8 disposed-witheachof'the-disc openings 1, and eachhaving a: sharp cutting edge 9 protruding beyond one side face lll of. the disc 5; a-log or slab feed hop= per having. av downwardly inclineddel-i-veryspout I I directed toward the disc face It On one side of the axis of the rotor shaft 6; a wedge lock bar I2 normally coacting with each knife blade 3 within its confining slot 1, to clamp the adjoining knife in operative position; an elongated holding member or plate I3 firmly attached to the other rotor disc face I4 adjacent to each slot '1' and wedge bar I2, by means of cap screws I3; a number of adjusting screws, not shown, normally coacting with each plate I3 and with the blunt rear end of the adjacent blade 3; and a number of locking screws 16 coacting with each wedge bar I2 and with the adjacent holding plate I3 to firmly clamp the adjacent blade 8 in cutting position.

The rotor discs 5 may be of any desirable diameter and may be provided with any suitable number of slots 7 and knives 8, and these knife carrier discs are normally rotatable at high speed in the direction of the arrow shown in Fig. 3, so as to rapidly revolve the successive knife blades 8 past the feed spout discharge opening. The blades or knives B are constructed of durable metal, but because of the heavy duty which these cutting blades perform, they must be frequently removed for regrinding of the cutting edges 9, or for renewal after repeated sharpening. As clearly indicated in Fig. 3, the successive knives 8 are not readily accessible at the zone of the feed spout II unless this spout is removed with considerable difiiculty, but the blades are freely accessible at all times at the opposite side of the rotor shaft 6, remote from this feed spout II. During normal operation of the chipper, the knife blades 8 are clamped firmly against the inclined bounding surfaces ll of the rotor slots 1 by the adjacent wedge bars I2 and locking screws I6, and these screws must be released in order to loosen the knives and to permit them to be withdrawn from their confining openings or slots.

In accordance with prior practice, it was customary to release the blade locking wedges, whenever a knife blade was to be removed, and to thereafter either utilize slow acting jack screws applied to the rear blunt end of the blade to lift it forwardly part way out of its confining slot, or to remove the blade holding plate so as to permit the knife to be withdrawn rearwardly from within its confining opening. Both of these methods were extremely tedious, and consumed a great deal of time, and they were also exceedingly dangerous when heavy blades or knives were being handled in connection with larger units.

In accordance with my present improvement, removal and insertion of the knife blades 8 is greatly facilitated and expedited, by providing each of the opposite ends of each blade 8 with a series of alined detents l8, and by also providing the opposite ends of each holding plate I3 with alined sockets I9, see Figs. 1 and 3. The reason for providing several sets of alined detents I8 in each blade 3, is to make the successive sets available as the blade is ground down during resharpening thereof. I additionally provide each elongated plate I3 with several parallel holes 20; and when it becomes desirable to remove a knife 8, the blade which is to be withdrawn should be positioned to the left of the central shaft axis and pointing upwardly as shown in Figs. 3 and 1 respectively.

After releasing the wedge bar I2 by loosening the locking screws l6 thereof, I apply to the pivot sockets 19, a U -shaped yoke or jack carrier 2| having axially adjustable pivot pins 22 carried by the free ends of the arms of the yoke and adapted to swingably coact with the alined sockets I9. A transverse bar 23 having parallel pins 24 which are slidably cooperable with the holes 23 of the adjacent plate l3 and which are adapted to contact the lower blunt end of the corresponding lade 3, is then positioned between the side arms of the yoke '2 I, and a hydraulic jack 25 is disposed centrally between the bar 23 and the lower parallel cross-bar of the U-shaped carrier 2|, see Figs. 1, 3 and 4. The hydraulic jack 25 may be of any conventional type, comprising a cylinder 26 having an oil supply reservoir therein and a base 2'? firmly attached to the carrier 2| as by welding, a plunger 23 slidable within the cylinder 26 and adapted to engage the transverse bar 23, a small manually operable pump 29 carried by the base 21 and being operable to force liquid from the supply reservoir to the displacement chamber beneath the plunger 28, and a by-pass valve 33 for permitting free return of the liquid from the displacement chamber to the supply reservoir whenever the plunger 23 is being lowered. It will be apparent, that by operating the jack 25 so as to elevate the plunger 28 thereof after the screws it have been loosened, the corresponding knife blade 3 may be forcibly lifted or elevated as illustrated in Figs. 1 and 4 so as to cause its sharpened or cutting edge 9 to move outwardly beyond the disc surface Ill any desired distance.

I also provide an improved blade clamping and handling tongs 3| such as shown in Figs. 1 and 2, for the purpose of effecting safe withdrawal of the loosened blades 3, and reinsertion thereof within the openings 1 of the rotor 5. These tongs 3| consist of a pair of similar hook elements 32 pivotally interconnected by means of a central pivot pin 33 and having their lower ends provided with points 34 adapted to engage the several sets of alined notches or detents I8 formed in the blades 8, while their upper ends are convnected by swingable links 35 with a suspension ring 35 which is adapted to coact with the hook of an ordinary overhead crane in an obvious manner. When the hook elements 32 are applied to a knife 8 as illustrated, and pulling or lifting force is applied to the ring 33, the points 34 will be driven into the detents l8 and the blade 8 will be firmly and safely suspended, but as an additional precaution, I may also provide a locking latch 31 swingably mounted upon one of the elements 32 by means of a, pivot 38 and cooperable with a pin 39 on the other, in order to positively lock the blade 8 within the tongs 3|, see Fig. 3.

While the mode of utilizing the relatively simple apparatus during the commercial exploitation of my improvement, should be quite clearly apparent from the foregoing detailed description, a short rsum of my improved system of removing and inserting chipper blades, will be given. When it becomes desirable to remove a knife 8 for regrinding or replacement, the worn knife blade should be positioned as shown in Fig. 3 on the side of the shaft 5 remote from the feed spout II, whereupon the blade adjusting screws should be removed from the holes 26 if no special holes have been provided, and the adjusting screws It should be loosened so as to release the wedge bar I2. The yoke 2! having the jack 25 secured thereto should then be suspended by means of the pivot pins 22 from the sockets I9 of the holding plate 13, and the cross-bar 23 with its parallel pins 24 should be applied to the holes 20 in the plate I3. The yoke 2| and jack 25 may then be swung into alinement with the bar 23 and pins 24, after which the pump 29 may be operated to cause the plunger 28 to move upwardly within the jack cylinder 26 and to raise the cross-bar 23 and the pins 24. Continued operation of the jack 25 will cause the pins 24 to force the knife blade 8 upwardly and to simultaneously slightly elevate the wedge bar 12 so as to free the blade 8 from lateral clamping pressure. As the blade 8 becomes elevated suificiently so as to expose the uppermost set of detents 18 therein, the clamping tongs 3| may be applied to these exposed detents or notches, and the blade 8 may thereafter be freely lifted from within the confining slot of the opening 1, with the aid of a crane applied to the ring 36. After the blade has been resharpened and is ready for reinsertion within the rotor 5, or in case a new blade 8 is to be inserted, the blade may again be brought into approximate position relative to the rotor 5 and it may be swung about the holding points 34 of the clamping tongs 3| so as to cause the lower blade end to enter the slot between the wedge block 12 and the rotor surface I1. Continued lowering of the blade will then cause it to slide into proper position, it being necessary of course to first lower the pins 24 with the aid of the by-pass valve 30 of the jack 25. The yoke 2| together with the jack 25, and the bar 23 together with its pins 24 may then be removed and the blade 8 may be subsequently again firmly clamped within the rotor '5 after it has been properly located with its cutting edge 9 protruding from the side surface ill of the rotor. In this manner, the knife blades 8 of the rotor 5 may be quickly and safely removed or inserted, with minimum loss of time and without danger of injuring the operator. As the blades 8 become worn and are reground, the successive side detents l8 will become effective for removal and insertion of the blades until they are sufliciently worn so as to make them unsatisfactory for further use.

From the foregoing detailed description of my improved apparatus for handling chipper blades or knives, it will be apparent that the present invention does in fact provide a system for safely and efi'ectively removing and inserting these blades. The several successive steps involved can be quickly and expeditiously performed with the aid of relatively simple and inexpensive mechanism, thereby preventing excessive loss of time in reconditioning or renewing the knives 8, and at the same time insuring utmost safety in the handling of the relatively sharp and heavy blades. With the aid of my improved apparatus for handling chipper blades, it is unnecessary to completely remove the normal clamping mechanisms, and it is also unnecessary to undesirably modify standard blade holding assemblages and knife blades. The improved apparatus is adapted to be quickly applied and removed, and the handling tongs 3| may either be manipulated by hand or with the aid of an ordinary crane so as to expedite the removal and reinsertion of the cutting blades 8 without disturbing the feed hopper spout l I of the chipper.

It should be understood that it is not desired to limit this invention to the exact details of construction of the apparatus or to the precise steps of the method, herein shown and described, for various modifications within the scope of the appended claims may occur to persons skilled in the art.

I claim:

1. A blade removing assemblage for a wood chipper having a rotary disc provided with a slot and a flat blade normally confined within the slot, an elongated blade holding plate secured to the disc near the slot and rearwardly of the blade, said plate having an opening therethrough directed toward the blunt end of the blade and also having alined pivots associated with its opposite ends, the assemblage comprising, a U-shaped yoke having opposite side arms swingably suspended from said plate pivots and also having a jack mounted thereon between said side arms, and a cross-bar slidably confined between said yoke arms and having a pin movable through said plate opening toward said blade by coaction with said jack to eject the blade from its confining slot.

2. A blade removing assemblage for a wood chipper having a rotary disc provided with a slot and a fiat blade normally confined within the slot and provided with alined notches at each of its opposite ends, an elongated blade holding plate secured to the disc and spanning the disc slot rearwardly of the blade, said plate having a pair of parallel openings therethrough directed toward the blade and also having alined pivots associated with its opposite ends, the assemblage comprising, a U-shaped yoke having opposite side arms swingably suspended from said plate pivots and also having a jack mounted thereon between said side arms, a cross-bar slidably confined between said yoke arms and having pins movable through said plate openings toward said blade by coaction with said jack to eject the notched side portions of the blade from the slot, and a pair of tongs cooperable with the exposed blade notches to completely withdraw the blade from the slot.

3. A blade removing assemblage for a wood chipper having a rotary disc provided with a slot and a flat blade normally confined within the slot, an elongated blade holding plate secured to the disc and spanning the disc slot rearwardly of the blade, said plate having a pair of laterally spaced parallel openings therethrough directed toward the blade and also having alined pivots associated with its opposite ends, the assemblage comprising, a U-shaped yoke having opposite side arms swingably suspended from said plate pivots and aiso having a hydraulic jack mounted thereon midwa between said plate openings, and a cross-bar slidably confined between said yoke arms and having parallel pins movable through said bar openings by coaction with said jack to eject the blade from its confining slot.

STANLEY D. PAYZER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,026,548 Allien May 14, 1912 1,376,414 Fransworth May 3, 1921 1,488,020 Malone Mar. 25, 1924 1,500,903 Shipley July 8, 1924 1,665,131 Ferrari Apr. 3, 1928 1,899,351 Overfelt Feb. 28, 1933 1,995,711 Irmis Mar. 26, 1935 2,089,795 Hodge Aug. 10, 1937 2,113,598 Mueller Apr. 12, 1938 2,247,665 Ottersland July 1, 1941 2,345,391 Grossett Mar. 28, 1944 2,388,799 Payzer Nov. 13, 1945 

